Numerous phenomena exhibit small motions that are invisible to the naked eye. By the application of computational amplification, such motions may be revealed, so that the motions may be visible to the naked eye.
Manipulating the local phase in coefficients of a complex steerable pyramid decomposition of an image sequence is an effective, robust method of amplifying small motions in video, but complex steerable pyramids may be overcomplete (for example, 21 times overcomplete) and costly to construct, using either a large number of filter taps (where a filter taps may correlate to coefficients of the filter, as known in the art) or a frequency domain construction where care is preferably taken to avoid spatial wrap-around artifacts.
However, the overcompleteness and high cost of implementing an existing complex steerable pyramid make existing phase-based video magnification slow to compute and nontrivial to implement in real time.